Well, I coulda helped you, but xero beat me to it! He is correct. Am wrestling is governed by USA Wrestling. The link he gave for them is also good.

I wrestled with a "Florida Amateur Wrestling Assoc." club. They also have a website... www.floridausawrestling.org You needed your USA wrestling card to compete, but not to train. I'd imagine your state has a similar org. Find that and they should be able to hook you up with a club that is open to adults. Tell them you want to wrestle "open division", which is 18+ and out of High School. There's a "Masters Division", which is over 35, but no one really wrestled in it in Florida.